Method of treating steel



Feb..9, 1943. McGLlNcY 2,310,703

METHOD OF TREATING STEQEL 1 Filed Jan. 8, 1941 Patented Feb. 9, 1943 7UNITED STATES PATENT OFFICE METHOD or TREATING sTEEL Lloyd F. McGlincy,Shaker Heights,hio, assignor to The American Steel and Wire Company ofNew Jersey, a corporation of New Jersey Application January 8, 1941,Serial No. 37 3,667

2 Claims.

This invention relates to a method of treating steel, and moreparticularly to cast steel which is in the form of an ingot.

In the conventional manufacture of steel the molten metal is poured fromthe furnace into a ladle from which it is teemed into molds. After.

the steel in the molds has solidified to a substantial degree, the ingotcomprised thereof is stripped from the mold and, while still highlycoarse and sensitive to distortion when drawn from the soaking pitpreparatory to rolling.

When in the blooming mill, the ingot is rapidly reduced in the earlypasses and this causes surface cracks which frequently must be chippedor burned off by scarfing. It is observed that the sides of the ingotnot in contact with the rolls of the blooming mill are more susceptibleto cracking. This is, of course, due to the heavy reduction in the earlypasses.- It is unquestionably true that lighter initial reductions wouldminimize some Figure 2 is an elevational view on the line,

11-11 of Figure 1.

According to the teachings of the present in-f vention, molten metal ofthe desired analysis is poured from the furnace into a ladle from whichit is teemed into the ingot molds. After the steel has substantiallysolidfied, the ingots comprised thereof are stripped and while stillhighly heated placed in a, soaking pit wherein the temperature from thecenter to the exterior surfaces thereof is equalized. After equalizationof temperature in the soaking pit, the ingots are ordinarily transferreddirectly from the blooming mill wherein the early passes are very heavy.Rather than minimizing cracking of the sides of the ingot by resortingto lighter initial reductions in the bloomng mill, with an attendantincrease in cost of production, the teachings of the inventioncontemplate the provision of instrumentalities which, after the ingothas been removed from the soaking pit preparatory to introducing intothe blooming mill, may be relied upon to improve or refine the grainstructure thereof. More specifically, there is provided means forpeening both sides of the ingot which are not in contact with the rollsof the blooming mill in the early reductions. 'This peening is completeon both sides of the ingot, removes all scale, and refines the coarsedendritic structure of the ingot skin so that it will be lesssusceptible to cracking during rolling, particuiarly on the initialbreakof this cracking on the sides of the ingot, but this is impracticalfrom the standpoint of economy.

It is among the objects of the present invention to provide a method oftreating steel which cracking of the ingot in the early passes of theblooming mill.

Another object is the accomplishmentof the foregoing in a manner whichis convenient and inexpensive.

lowing detailed description, and in the drawing,'

for simplicity, like reference numerals have been employed to designatethe same parts throughout the several views,

In said drawing:

Figure 1 is a diagrammatic, fragmentary plan of apparatus which may beused to practice the method of the present invention; and

down passes through the rolls of the blooming mill.

Referring more particularly to the drawing, I have illustrateddiagrammatically a form of apparatus which may be used to practice themethod of the present invention. This apparatus is disposed above thefeed rolls 2 on the approach table of the blooming mill and comprises,on-

either side of the line of pass therethrough, a series of pneumaticallyoperated hammers 3 which are constructed and arranged in such staggeredrelationship as to be able to completely peen both sides of the ingotimmeidately prior to the passage thereof into the rolls of the bloomingmill. The manner of operation of these pneumatic hammers 3 is entirelyconventional, as are the structural details thereof, and as such theseaspects form no part of the present invention.

While I have shown and described certain specific embodiments of thepresent invention, it will be seen that I do not wish to be limitedexactly thereto. since various modifications may be made withoutdeparting from the scope of the invention, as defined by the followingclaims.

I claim:

1. The method of treating steel which comprises molding the steel intoan ingot; permitting the ingot to substantially solidify; stripping theingot from. its mold; placing the ingot in a heated vessel; permittingthe temperature of the ingot while in the heated vessel to besubstantially equalized throughout to the temperature required forforging but materially below the temperature of solidification; removingthe ingot from the heated vessel; peening the surface of the ingot whileit is still at forging temperature and materially below the temperatureoi solidification, whereby the scale is removed and the grain structureof the skin of the ingot is refined; and rolling the ingot to thedesired shape while it is still at iorging temperature.

2. The method of treating steel which comprises molding the steel intoan ingot: permitting the ingot to substantially solidify; stripping theingot from its mold; placing the ingot in a heated vessel; permittingthe tempera-tine voi the ingot while in the heated vessel to besubstantially equalized throughout to the temperature required forforging but materially below the temperature of solidiflcationj removingthe ingot from the heated vessel; peening the surface of the ingot whileit is still at forging temperature and materially below the temperatureof solidification, whereby the scale is removed and the grain structureof the skin of the ingot is refined; and rolling the ingot to thedesired shape while it is still at forging temperature, said peeningbeing performed without material reduction in cross-sectional area.

LLOYD F. MCGLINCY.

